I. Field of the Invention
The present invention relates to an alarm or signaling system for being attached to mailboxes, and more particularly the invention relates to electrical alarms which are actuated by the opening of the mailbox doors, such as for inserting and removing mail therefrom.
II. Description of the Prior Art
In years past, roadside mailboxes were common both in rural and in newly developing urban areas. More recently the U.S. Postal Service has allowed homeowners to relocate their mailboxes to locations generally adjacent to the front door of the house in order to improve the convenience to the homeowner. Unfortunately, this newer location requires the postal carrier either to walk between the houses or to drive a mail truck along a circuitous route between the houses. Since the U.S. Postal Service is attempting to improve efficiency, the use of pedestrian mail delivery is being discouraged, and in view of the substantially increased prices of petroleum products in recent years the circuitous traveling of postal vehicles should be minimized in delivering the mail.
Several studies are presently being conducted by the U.S. Postal Service and the Department of Energy to re-institute roadside or curbside mailboxes. In this manner the mail may be delivered by the Postal Service in a more efficient manner. That is, the Postal delivery vehicle will merely travel along one side of the road and the mail will be delivered to each business or residence through a curbside/roadside mailbox. The use of these mailboxes in everyday business and household applications requires several adaptations and adjustments. For example, it is anticipated that the theft of important documents, checks and money orders sent through the mail will increase when curbside/roadside mailboxes are again instituted. This increase is predicted because the occupant of the dwelling is usually aware through visual and auditory perception of the delivery of the mail, whereas these visual and auditory perceptions will be substantially reduced when the mailbox is located further from the dwelling. Furthermore, thieves are usually thought to be more reluctant to come into close proximity with a dwelling in order to steal contents of a mailbox attached thereto as compared with the ease of theft from a detached mailbox.
It is therefore an object of the present invention to provide additional visual and/or auditory warnings to the occupant of the dwelling that the U.S. Postal Service has deposited mail into the curbside/roadside mailbox.
The prior art is replete with various types of mailbox alarms. However, as a group these mailbox alarms are quite complicated in their construction and they usually require that the mailbox be originally designed in order to incorporate the sensing mechanism for the alarm. This should be contrasted with the ready availability of the standard curbside/roadside mailbox which can be fitted with a suitable sensor. It is therefore a second object of the present invention to provide a mailbox alarm of the type which can be either incorporated into the mailbox at the time of production, or in the alternative of the type to be coupled to an already existing curbside/roadside mailbox.
One common example of a mailbox alarm of the type which must be incorporated into the mailbox at the time of production, is described by Korth in U.S. Pat. No. 2,477,379. In this device a lip of the lid of the mailbox is forced into communication with switching elements when the lid of the mailbox is opened. However, the switching device is located inside the mailbox which is not of the type readily adaptable to curbside/roadside use.
A second example of an alarm of the type to be attached to mailboxes which are typically attached to the house is described by Whildin in U.S. Pat. Nos. 2,759,057 and 3,040,141. These devices place the switch inside the cavity within the mailbox. The switch is then actuated by a lip affixed to the underneath side of the door closing over the entranceway into the mailbox. This type of alarm system is only suitable for incorporation into mailboxes at the time of production and is not suitable for mailboxes of the type normally located at curbside.
Lang, in U.S. Pat. No. 1,808,235, discloses a mailbox alarm which utilizes the door of the mailbox as one of the electrical elements of the switch. A tongue of the door is moved into electrical contact with another portion of the backside of the mailbox as the entryway door of the mailbox is opened. This switch is immediately deactivated when the door of the mailbox is closed. Alarms and switches of this type are not well suited for normal security applications because if the occupant of the business or household is inadvertently inattentive to the mailbox alarm, the occupant will not have any indication that the mail has been delivered. Thus, this type of impulse or short period alarm is not best suited to the objects of the present invention.
Darvishian, in U.S. Pat. No. 3,935,994, discloses a custom designed mailbox which incorporates an electrical switch which is actuated by a main section of the door which closes over the entryway into the mailbox. Because of the location of the actuating switch, alarm systems of this type are not well suited for retrofit applications into existing curbside/roadside mailboxes. Various other designs of alarm systems of the type more suitable for non-roadside mailboxes are disclosed by Donadio in U.S. Pat. No. 2,480,288, Holmgren, in U.S. Pat. No. 1,911,621, Miller in U.S. Pat. No. 1,157,949, Landrum, in U.S. Pat. No. 1,442,578, Hopkins in U.S. Pat. No. 1,021,100 and Hill in U.S. Pat. No. 3,009,139.
Various mailbox alarm systems have been designed specifically for mailboxes of the type normally located by the side of the road. For example, U.S. Pat. No. 3,707,260 discloses a complex mechanical lever and pivot system which actuates a radio frequency transmitter responsive to the opening of the door covering the entranceway to the storage compartment within the mailbox. Again, this type of complex alarm system is not suitable for easy and economical retrofit applications to existing detached mailboxes.
Tracy, in U.S. Pat. No. 322,665, discloses a mailbox alarm system which locates a sensor switch inside the mailbox and adjacent to a lip of the door for the entryway of the mailbox. This type of sensor switch requires careful placement and alignment within the mailbox, and is therefore not well suited for retrofit applications. U.S. Pat. Nos. 3,606,141 and 918,530 disclose mechanical signal devices which employ flags or other non-electrical signaling devices for indicating that the door to the mailbox has been opened. U.S. Pat. Nos. 1,112,346, 1,019,554 and 1,005,004 disclose electro-mechanical mailbox alarms of the type which may be coupled to curbside/roadside mailboxes. However, these devices again are not suitable for retrofit applications to existing mailboxes of this type. Grindle, in U.S. Pat. No. 1,037,470 discloses a mailbox alarm which senses the weight of the mail deposited within the mailbox in order to actuate the alarm mechanism.
A careful review of the preceding prior art references will clearly indicate that a new approach must be taken to the design of a mailbox alarm system. The alarm actuator must be inexpensive to produce and easily attached to the mailbox in a position which does not require work in confined spaces. The alarm switch sensor must be rugged in order to survive negligent or inattentive abuse, and must survive extended exposure to inclement weather. It is furthermore desirable that the sensor switch not be located within the mailbox so as not to reduce the volume available for storage of the mail therein. It is most important that the switch sensor be easily coupled to pre-existing curbside/roadside mailboxes without the use of complex drilling jigs or other uncommon machinery or tools.